第17题: [单项选择]The incidence of this disease has been greatly reduced thanks to our health care program. A. seriousness B. frequency of occurrence C. mortality D. cure rate 参考答案:B 答案解析:seriousness严肃，认真；frequency of occurrence发生频率；morality死亡率；cure rate治愈率。
第19题:[单选题]He was not asked to take on the chairmanship of the society,（ ）insufficiently popular with all members. A.being considered B.considering C.to be considered D.having considered 参考答案:A 该句考查非谓语动词。该句主语为He，consider与主语之间的关系是被动关系，因此排除B、D选项，而选项C表示将来，故答案为A。
